Process for preparing improved acid derivatives of hydrocarbon oils and products thereof



Patented Mar. 22, 1938 UNITED A STATES PATENT OFFICE Stewart 0. Fultonand Hans G. Vesterdal, Elizabeth, N. J., assignors to Standard OilDevelopment Company, a corporation of Dela-- ware No Drawing.Application June 2, 1934,

Serial No. 728,770

13 Claims.

This invention relates to methods for preparing improved derivatives ofhydrocarbon oils with strong mineral acids and to the products thereof,

and more particularly to the production of improved wetting agents anddetergents.-

The treatment of hydrocarbon'oils with strong and fuming sulfuric acidand sulfuric anhydride for the purpose of producing refined oils haslong been known. The sulfuric derivatives so formed and the saltsthereof have been used as wetting agents, detergents, fat splittingagents, tanning agents, emulsifying agents, de-emulsifiers, and forother. purposes. The quality of these sulfuric derivatives issubstantially increased b;' conducting the oil-acid reaction at lowtemperatures, usually below 50 F. and preferably below 40 F, and even 20F. or 10 F. when using strong sulfuric reagents such as concentratedsulfuric acid, fuming acid and sulfuric 2o anhydride.

- It has now been found that a. still further improvement in the qualityof the sulfuric derivatives is obtained if precautions are taken to keepthe acid-oil reaction mixture at or below 25 the treating temperatureuntil the strong sulfuric reagent is removed. It is preferable that thetemperature of the reaction mixture be not allowed to rise above thetreating temperature until all free sulfuric 'anhydride has been com- 30pletely removed and the strength of the free sulfuric acid remaining hasbeen reduced below about 80% and preferably to between 30 and 60%. Thisstrength of acid is based on the total amounts of free acid and waterpresent in 35 the reaction mixture. The reduction in the strength of theacid in contact with the organic reaction products may be accomplishedby neutralization with suitable bases, by dilution with water, byselective solvents to remove the acid 40 or the organic compounds, byany combination of such means, or by any other means effective toeliminate free acid and to decrease its capacity to cause furtherreaction with the initial materials or the components of the reactionmixture.

45 Since such neutralization and dilution operationsresult in a markedevolution ofheat it is necessary either to 'pre-chill the reagents ordiluents or both to a very 'low temperature or else to supply positivecooling continuously during the 50 reduction in strength of the acid.

This invention may be used to prepare improved sulfuric derivatives,detergents, wetting agents, and the like, from all types of hydrocarbonoils of preferably above about 8 carbon atoms 55 per molecule and whichundergo reaction with strong sulfuric reagents at low temperatures.Aromatic, naphthenic and mixed base petroleum oils, and productsobtained therefrom by distillation, extraction, cracking,dehydrogenation, destructive hydrogenation, limited oxidation, or anycombination of such processes are suitable for treatment with strongsulphuric reagents according to this invention. Also suitable are theacid reactive fractions obtained from parafiin wax, petrolatum,parafflnic oils and white oils by crack- 10 ing, dehydrogenation,destructive hydrogenation, limited oxidation, and like processesSynthetic acid reactive oils, such as are obtained by polymerization ofnormally gaseous and light liquid olefines by any suitablepolymerization and/or condensation method, for example using acid orhalide catalysts and/or contact surfaces, high pressures andtemperatures, may also be used.

The sulfuric derivatives obtained in the acidoil reaction are believedto be in the form of sulfonic acids or sulfuric esters or mixtures ofboth. These derivatives may be separated from the reaction mixtureaccording to the present invention in the form of the acids and acidesters or they may be neutralized with suitable bases during theneutralization of the free sulfuric acid or after separation therefromand may be obtained in the form of salts or soaps. Both types ofproducts are markedly superior to the sulfonic acids, sulfonates, etc.,obtained in the ordinary treating of hydrocarbon oils with sulfuricacid.'

The sulfuric derivatives obtained by this invention from hydrocarbonsand products thereof having a relatively long and straight chain ofabout 10 to 18 or more carbon atoms, with few and preferably shortbranches, may'be used to prepare highly effective detergents byneutralization with suitable bases, such as the basic compounds of thealkalies and ammonia. Suitable 40 stocks for the preparation of the acidderivatives are those obtained by cracking and/or dehydrogenation ofparaflins, such as paraffin wax and petrolatum, preferably underconditions avoiding polymerization and rearrangement of the unsaturatedproducts formed. The use of such stocks, particularly cracked parafiins,in the preparation of soaps of sulfuric derivatives thereof asdetergents, is claimed in copending application Serial No. 704,749,filed December 30, 1933, by William J. Sweeney. The calcium salts ofthese derivatives are soluble in water, permitting the use of thedetergents in hard waters and even in sea water. In fact, the detergentproper- .ties of these derivatives are often improved by 5 valent metalsare generally preferred for this use.

Compounds having adverse physiological effects should obviously not beused in preparing soaps to be used in contact with living organisms. Thesalts of the weaker acids, such as the borate's,

acetates and salts of other organic acids, also serve as bufiers toprevent the development of acidity in the event that the detergents maycontain readily hydrolyzable sulfuric derivatives. Detergents may alsobe prepared by using basic compounds of the above metals to.neutralizewholly or partly the sulfuric derivatives. The

.magnesium soap oi. the sulfuric derivatives of cracked wax, forexample, is a particularly effective detergent.

The detergents having about 18 or more carbon atoms in the chaindissolve only slowly in water. but can be dissolved or dispersed muchmore readily in the presence of a small amount of oil soluble sulfonatesor other suitable emulsifying agents, or on addition of a few percent ofan alcohol to the water. These solution aids may be added separately tothe bath or may be mixed with the detergents, and the emulsifying agentsare used preferably in a minor proportion to the detergents in eithercase.

The sulfuric derivatives obtained by this invention from hydrocarbons ofmore than about 8 carbon atoms permolecule and having a more .or vaporphase, at reduced, atmospheric or increased pressures and may be oncethrough or cyclic. It is preferably conducted under conditions favoringthe production of unsatiu'atedproducts, and with as littlepolymerization and condensation as possible, for example, by a quickpassage through a narrow cracking tube. More highly cracked stocks,however, such as cycle stocks which have been repeatedly cracked, mayalso be used. These derivatives of branched and cyclic hydrocarbons aresuperior wetting, dis- Dersing and emulsifying agents having extendedthe like.

The following examples are presented to illustrate suitable methods forconducting the process of this invention:

Example 1.

A fraction of cracked petrolatum distilling between 360 and 600 F. isobtained in an atmospheric pressure batch destructive distillation. 36liters of this distillate, containing about of olefines, are treated atabout 12 to 20 F. with 7 kilograms of fuming sulphuric acid containing20% sulphuric anhydride, by slow addition of acid with cooling andvigorous agitation during about three hours agitation. The acid is thenneutralized by careful addition of sodium hydroxide with continuedagitation and cooling to maintain the temperature below 20 F. until thesulphuric acid strength is below about 60%. On completion ofneutralization, 18 liters of isopropyl' alcohol are added with stirringand the mixture is allowed to stand. Three layers then form, a loweraqueous layer of mineral salts, a middle alcoholic layer containing mostof the sodium soaps of the sulphuric acid derivatives formed, and anupper oily layer of unreacted hydrocarbons containin some soap. Thethree layers are separately withdrawn. The soap is extracted from theupper layer with 50% aqueous isopropyl alcohol, and the extract is addedto the middle layer. Sufilcient ammonia is added to this solution tomaintain a slight excess of ammonia throughout the following dryingoperation. The alcohol solution is then evaporated to dryness on a drumdryer, at a temperature of about 120? F. There are then obtained 4.5kilograms of soap, which consists largely of sodium salts of sulphatedolefines. This soap is of a very light amber color, and givespractically colorless aqueous solutions in concentratio'ns'suitable forwashing and laundering purtive detergent and is effective in soft orhard water. l

Example 2 pare a sodium soap by the same procedure there used. From 22liters of the cracked wax fraction is obtained 6.6 kilograms of soap,using only 4.5 kilograms of fuming. sulphuric acid. This soap issuperior in laundering characteristics even to that prepared fromcracked petrolatum in Example 1, and shows substantially better sudsingand cleaning characteristics in hard water. I I I Example 3 n A TalangAkar crude oil was cracked by being passed once through a cracking zonemaintained at a pressure 'of 250' pounds per square inch and atemperature'of 850 F. The cracked gas oil obtained after distilling offthe gasoline from the cracked product was further distilled to obtain adistillate fraction of 35 A. P. 1., representing about 12% of thecracked gasoil. 100 c. c. of this distillate fraction was cooled to 5 F.and 200 grams of fuming sulfuric acid containing 20% sulfuric anhydridewas added s lowly with continued agitation and cooling to maintain thetemperature of the reaction mixture. at 5 F. The reaction mixture wasthen slowly diluted with cold water; with continued cooling to removethe heat formed on dilution and to maintain the temperature of themixture. belowabout 32 F., the

temperature increasing roughly asthe dilution progressed, to reduce'theconcentration of free sulphuric acid to about 60% (based on total freeacid and water) The mixture was then allowed to settle and a loweraqueous layer of sulphuric acid formed and was removed. The upper layerwas then neutralized by addition of a 15% aqueous solution of causticsoda and enough isopropyl alcohol was added to cause the formation ofthree separate layers, an upper oily layer, a middle alcoholic layer,and a lower aqueous layer. The top oil layer and the bottom aqueous saltsolution layer were separately removed. The middle layer, containing thesoaps of the sulfuric derivatives of the oil in solution in alcohol, wasevapo-' rated to remove" the alcohol. There were thus ob.- tained asevaporation residue 8'7 grams of a dry soap having wetting outproperties equivalent to sodium salts of sulfated hexaand octa-decylalcohols and having good detersive properties.

Example 4 A Pennsylvania crude is fractionated by distilusual methodsand used as a high quality white or medicinal oil. The soaps obtainedhave equal wetting out properties, and usually a somewhat less detersiveaction than those obtained from cracked oils as described in Example 3.Other crudes, including the Mid-Continent or mixed base and thenaphthenic type crudes, may be similarly treated to prepare improvedsulfuric derivatives therefrom. It is generally desirable in using suchcrudes to give the crude or the distillate fraction a preliminarytreatment with concentrated sulfuric acid to remove asphaltic matter.The soaps then obtained according to the present invention are ofimproved quality and A color.

The acid oil reaction may be conducted with strong or fuming acid orwith sulfuric anhydride alone or with other suitable solvents ordiluents'. While the reaction may be carried out at a substantiallyuniform low temperature, it may be conducted to advantage by contactingthe sulfuric reagent and the oil at a very low temperature, say 0 F. oreven lower, and then permitting the mixture to warm up to the maximumtemperature of about 20 to 50 F. desired. The oil may also be firstmixed with a relatively weak sulfuric reagent, say a diluted sulfuricacid or a fuming acid of low concentration, and the strength of thesulfuric reagent may then be increased while in contact with the oil bythe addition, preferably gradually, of a stronger sulfuric agent such asstrongly fuming acid or sulfuric anhydride. This method of treatment isclaimed in copending application Serial No. 70 L757, filed December 30,1933 by one of the present inventors. ne'm'milder preliminary treatmentapparently serves to convert the more highly reactive components of theoil such as dioleflnes and tertiary ed products of the limited oxidationof hydrocarbons such as petroleum, white oil and paramn wax: coal tardistillates, ethers, esters, aldehydes, ketones and hydroxy organiccompounds enerally, phenols, naphthenic and other acids, thickened orpolymerized animal and vegetable oils, resins, rosin, terpenes; alsoamines, sulfur compounds halogenated compounds such as'chlorinated wax;also aromatic compounds such as naphthalene, diphenyl, diphenyl oxide.and otherderivatives of aromatic compounds, and the like.

The cooling during either the acid-oil reaction or the subsequentneutralization or dilution steps or both may be conducted by eitherdirect or indirect heat exchange with cooling liquids. For example, aninert diluent boiling at a low temperature, such as propane, butane orpentane or mixtures thereof, or other low boiling hydrocarbons, ether,carbon tetrachloride and other diluents which are inert or react onlyslowly with the sulfuric reagent, may be added to the hydrocarbon oilsto be treated in suflicient amounts so that by evaporation itremoveszthe heat generated in the reaction mixture and maintains thetemperature thereof at any desired level. The temperature in such casesmay be conveniently con-.

trolled by adjusting the pressure maintained on I the reaction zone.Pressures above atmospheric may be used with the low boilingrefrigerants, and

pressures below atmospheric, even a high vacuum,

may be used with high boiling refrigerants.

Other refrigerants such as liquid sulfur dioxide the mixture at thedesired low temperature.

Suitable bases include the oxides, hydroxides,

carbonates and other basic compounds of the alkali and alkaline earthand other suitable metals,-ammonium and the amines, alkyl amines,,alkylol amines and other organic bases and mixtures of any suchcompounds. Liquid ammonia can be used both as a neutralizing agent and are frigerant during this operation.

The sulfuric derivatives and the neutralized products thereof obtainedfrom clean hydrocarbon oils, that is, free from asphaltic and tarrymatter, will usually be of suitable color and purity for immediate useas wetting agents or detergents, etc., of high quality. However, ifdirty .stocks are used, or treating, neutralizing or drying temperaturesare permitted to run too high,

discolored products may result. These may be purified by treatment withclay, active carbon, by salting out of a saturated salt solution ofsodium chloride or sulfate, for example, by the use of selectivesolvents, such as aqueous alcohols, for the soaps and/or preferablyaromatic hydrocarbon oils and the like, for the tars; by treatment withperoxides, and other soap refining practices. The addition of solublecalcium or other alkaline earth or heavier polyvalent metal salts to anaqueous solution of discolored sulfuric derivatives or theircorresponding alkali soaps also serves to precipitate color bodies. Theprecipitate maybe removed by settling, centrifugation, filtration,dialysis, etc., and a light colored sulfuric derivative or soaprecovered from the purified solution by drying, solvent extraction,salting out, and other methods.

In many cases the neutralized sulfuric deriva-- tives contain unstablebodies, as evidenced by the development of acidity in aqueous solutionof such derivatives on standing even at room temperature, and morerapidly on heating such solution to boiling. Such unstable bodies can beremoved and the products rendered stable even on long continued boilingby the use of a limited hydrolysis treatment in which an aqueous oralcoholic solution of the soap containing a small amount of ahydrolyzing agent, preferably one or two percent of sodium hydroxide orother strong alkali, is heated to a suitable temperature to remove theunstable compounds, as described and claimed in copending applicationSerial No. 722,838 filed April 28, 1934, Patent No. 2,049,055, July 28,1936, by the present inventors.

The amount of unstable compounds in the products can begreatly decreasedby conducting the acid treating of the hydrocarbon oil and thesubsequent removal of excess sulfuric reagent so as to keep the time ofcontact of oil and strong reagent to a minimum. The oil and sulfuricreagent may be contacted in a homogenizer rotating at high velocity, say1,000 to 10,000 R. P. M., or by passing stream of oil and sulfuricreagent at a rapid rate through a zone containing mixing baiiles. Theexcess reagent may then be removed by rapid dilution and/orneutralization and/or by the use of a centrifuge to separate phases ofdifferent density.

In case it is not desired to stabilize completely the products, thedevelopment of acidity therein and diminution in yield can be preventedby conductlrg the drying operation in the presence of a slight excess ofalkali, as described and claimed in copending application Serial No.704,790, filed December 30, 1933 by Hans G. Vesterdal.

The sulfuric derivatives and the neutralized products or soaps obtainedtherefrom, are suitable for use as valuable detergents or wetting'agents, according to their composition, as described above. They mayalso be used as tanning agents, emulsifiers, emulsion breakers, andgenerally in whole or partial substitution for ordinary fat acid soapsand for the green, or water soluble, sulfonates. They may also be usedin admixture with other wetting agents and detergents, such as theordinary petroleum acid sludge sulphonates, the sulphates of fattyalcohols, hydroxy acids and the like, fatty acid soaps, alkalies such aswashing soda and ammonia, fillers, abrasives, dyes, perfumes, organicsolvents and other addition products in the preparation of wetting andcleansing compositions, laundry and toilet preparations, bar soaps, soappowders, liquid soaps, dry cleaner soaps, and like compositions.

These sulfuric derivatives may also be used generally as improvedsubstitutes for the water soluble sulfonic acids and sulfonatesheretofore obtained from acid treating. of petroleum oils under ordinaryconditions.

This invention is not to be limited to any illustrations, examples ortheoretical explanations which have been presented herein solely forpurpose of illustration, but is limited only by the following claims inwhich it is desired .to claim all novelty insofar as the prior artpermits.

We claim:

1. Process for preparing improved wetting agents and detergents,comprising treating an acid reactive petroleum oii fraction of more thaneight carbon atoms per molecule with fuming sulfuric acid at a reactiontemperature below about 50 F. to produce a sulfuric derivative of areactive component of said oil, reducing the strength of free sulfuricacid in the reaction mixture to below about 60% while maintaining thetemperature of the reaction mixture continuously below about 50 F. andneutralizing the said sulfuric derivative with a suitable base to form awater soluble product thereof.

2. Process according to claim 1 in which the said petroleum oil is avirgin oil. i

3. Process according to claim 1 in which th said petroleum oil is avirgin distillate fraction and the said reaction temperature ismaintained below about 20 F.

4. Process according to claim 1 in which the said petroleum oil is acracked fraction of petroleum oil.

5. Process according to claim 1 in which the said petroleum oil is acracked gas oil and the.

about 10 F.

6. Process for preparing improved wetting agents and detergentscomprising reacting an acid reactive petroleum fraction of more thaneight carbon atoms per molecule with an excess of fuming sulfuric acidat a temperature below about 50 F., reducing the strength of freesulfuric acid in the reaction mixture to below about 60% whilemaintaining the temperature of the reaction mixture continuously belowabout 50 F. and neutralizing the resulting sulfuric derivatives with asuitable base to form a water soluble product thereof.

'7. Process for preparing improved detergents comprising treating amixture of olefins of more than eight carbon atoms per molecule obtainedby cracking a parailln with fuming sulfuric acid in excess at a reactiontemperature below about 40 F., reducing the strength of the freesulfuric acid in the reaction mixture to below about 60% whilecontinuously maintaining the temperature of the reaction mixture belowabout 40 F. and neutralizing the resulting sulfuric derivatives with asuitable base to form a water soluble product thereof.

8. Process for preparing improved detergents comprising treating amixture of olefins of more than eight carbon atoms per molecule obtainedby cracking paraflin.wax, with fuming sulfuric acid in excess at areaction temperature below about 40 F., reducing the strength of thefree sulfuric acid in the reaction mixture to below about 60% whilecontinuously maintaining the temperature of the reaction mixture belowabout 40 F. and neutralizing the resulting sulfuric derivatives with asuitable base to form a water soluble product thereof.

9. Process for preparing improved detergents comprising treating amixture of olefins of more than eight carbon atoms per molecule obtainedby cracking petrolatum with fuming sulfuric acid at a reactiontemperature below about 20 F., reducing the strength of free sulfuricacid in the reaction mixture to below about 60% while maintaining thetemperature of the reaction mixture continuously below about 20 F. andneutralizing the resulting sulfuric derivatives with a suitable base toform a water soluble product thereof.

I 10. Improved wetting agent and detergent comprising salts of sulfuricderivatives of acid reactive petroleum oils prepared according to Vclaim 1.

11. Improved detergents comprising salts of sulfuric derivatives ofcracked paraflin prepared according to claim 7.

12. Improved detergents comprising salts of sulfuric'derivatives ofcracked paraflin wax prepared according to claim 8.

STEWART C. FULTON. HANS G. VESTERDAL.

